Mamatha B Salimath and Onkarappa
Actinomycetes are the most economically and biotechnologically valuable prokaryotes and are responsible for the production of about half of the discovered bioactive secondary metabolites, antibiotics, anticancer agents and enzymes. The present study was successful in characterizing 25 Streptomycetes isolates inhabiting Agumbe province, of Western Ghats soil of Karnataka, India, for potential source of L-asparaginase enzyme. L- Asparaginase (L-asparagine amido hydrolase E.C.220.127.116.11) is an extracellular enzyme has anti-carcinogenic potential, received increasing awareness in the current years because of its use as an effective agent against Acute Lymphocytic Leukemia (ALL). L-asparagine is a source of essential amino acid necessary for the growth of leukemic cells in higher amounts. Depletion of L-asparagine from the circulatory blood leads to death of malignant cells. Streptomyces isolates have been collected from soil samples by serial dilution and plating method employing Starch Casein Nitrate agar and ISP media. They were identified based on cultural, morphological and biochemical characteristics. When primarily screened for L-asparaginase production by Rapid plate assay using Modified M9 medium containing L-asparagine and Phenol red as indicator, 23 isolates were found to be positive by showing change in color of medium from yellow to pink. Strain V17 isolate proved to be potent producer of the enzyme with higher amount of enzyme up to 22.45 IU/ml. About 92% of the tested isolates were positive for anti-cancerous potential, indicating the Western Ghats soils as potential sources for anti-cancerous agents. Further studies on purification and characterization of enzyme are under progress.